Refrigerating apparatus



June 30, 1959 2,892,325

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June 30, 1959 D. J. TIMMER REFRIGERATING APPARATUS 3 Sheets-Sheet 2 Filed April 1 0, ,1957

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REFRIGERATING APPARATUS Filed April 10, 1957 3 Sheets-Sheet 5 Fig. 6

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United States Patent O REFRIGERATING APPARATUS David J. Timmer, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application April 10, 1957, Serial No. 651,989

8 Claims. (Cl. 62-456) 'lhis invention relates to refrigeration and particularly to a method of and means for providing in a refrigerating system having a combined roll-forged condenser and evaporator member therein arefrigerant restrictor.

Recently it has been proposed to form a capillary passage within a roll-forged member having portions thereof forming two or more elements in a refrigerating system which passage provides a refrigerant restrictor for the system. This proposal while being meritorious is ditiicult to carry out and has, up tothe present time, not been economical because of loss due to a considerable number of roll-forged members being Yrejected and/or scrapped. Problems of properly dilating and flushing out a capillary passage formed in a roll-forged plate member therefore renders it desirable, at least temporarily, to provide a cheaper and novel method of and arrangement for incorporating a separate capillary restrictor in the construction of a roll-forged member of the type disclosed in the patent to I. W. Jacobs and R. E. Gould #2,779,168, dated January 29, 1957 to render such a plate member immediately practical for .use in a refrigerating system. In this respect the present invention is directed to an improvement over that disclosed yin my copending application S.N. 585,905, tiled May 18, 1956, entitled Refrigerating Apparatus, and assigned to the assignee of this application, now Patent No. 2,806,- 359, issued September 17, 1957.

An object of my invention is to provide a low-cost practical combined unit or member forming a plurality of heat exchanger elements of a closed refrigerating system with a refrigerant ow control means which while being separate from the member is concealed therein.

Another object of my invention is to provide a refrigerant pressure reducer or restrictor for a roll-forged onepiece plate member, forming spaced apart heat exchanger elements of a closed refrigerating system, that is separate from the member but Wholly contained in and extends along integral portions thereof from one element to another for controlling flow of refrigerant therebetween and which member thereafter requires a minimum of Weld joints to seal the restrictor therein.

A further object of my invention is to sever or cut away a single part or segment of a roll-forged plate member of a refrigerating system along with an end of a passage or duct therein for exposing the end of the duct, to insert a predetermined length of tubing separate from the member into the exposed end of the duct, to provide a seal between at least a portion of the tubing and inner wall surfaces of the duct in which the tubing is disposed and to thereafter weld the single opening of the duct so that all refrigerant entering same will be directed through the tube which has an inside diameter of substantially capillary size relative to other passages and/or ducts formed in the member and controls ow of refrigerant between these other passages.

A still further and more specific object of my invention is to provide in a passage or duct of a roll-forged one- 2,892,325 Patented June 30, 1959 ICC piece plate member for a refrigerating system a refrigerant restrictor in the form of a length of tubing having a straight section and an integral coiled section both wholly disposed in the duct and to seal at least the straight section of the tube to inner wall surfaces of the duct without Welding or brazing whereby to reduce the overall length of the tube and obtain proper restricting to iiow of refrigerant to a given size evaporator portion of the member.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Figure 1 is a front view of a refrigerator having a rollforged member of the present invention associated there,- with showing the refrigerator door open; Y

Figure 2 is an enlarged fragmentary sectional view taken on the line 2-2 of Figure 1 showing the mounting of different integral portions of the member upon and within the refrigerator cabinet;

Figure 3 is a broken rear view of the refrigerator disclosed in Figures l and 2;

Figure 4 is a plan view of a trimmed roll-forged plate member after passages formed therein have been dilated;

Figure 5 is a view similar to Figure 4 with a part or segment of the roll-forged plate member inwardly of its peripheral edges severed or cut away to expose or open i an end of a certain passage or duct therein to an edge portion of the member.

Figure 6 is an enlarged fragmentary or broken View similar to Figure 5 sho-Wing a filter-dryer and capillary tube disposed in a duct of the roll-forged plate member in accordance with my invention with the member ready to be bent to provide two or more elements of a refrig-A erating system; and

Figure 7 is an enlarged fragmentary and broken sectional view taken on the line 7-7 of Figure 6 to more clearly illustrate the invention.

Referring to the drawings l show in Figure l thereof a refrigerating apparatus including a refrigerator cabinet 10 having a plurality of insulated walls forming a food storage chamber 11 therein provided with the usual vertically spaced apart food supporting shelves. Chamber 11 has a front access opening normally closed by an insulated door 12. A sheet metal refrigerant evaporator portion of a two-portioned integral roll-forged member of a refrigerating system, associated with cabinet 10 and to be hereinafter described, is located in the upper part of chamber 11. This evaporator forms walls of a sharp freezing compartment in chamber 11 and is preferably provided with a front closure door (not shown) as is conventional in the art. The evaporator is adapted to chill air and cause its circulation throughout the interior of chamber 1,1 for cooling food products stored therein. The rear insulated wall 14 of-cabinet 10 has an opening therein, closed by removable inner and outer panels 16 and 17 respectively ha-ving loose or bulk insulating material 1S therebetween (see Figure 2), for a purpose to become apparent hereinafter. with a machine compartment 19 below the food storage chamber 11. The refrigerating system associated with cabinet 10 comprises a sealed casing 20, containing an 'electric motor and a compressor driven thereby (not shown) and a roll-forged member having refrigerant passages contained therein and being bent or arranged to provide the system with an evaporator and a condenser. Casing 2) is mounted in the machine compartment 19 of cabinet 10 in any suitable or conventional manner and the roll-forged member is clamped to the Cabinet 10 is provided i 2,892,325 y n A casing, as shown Yand fully described in the Iacobs and Gould patent hereinbefore referred to, so that refrigerant passages in the member will be connected to and cornmunicate with the interior of the casing.

In Figure 4 of the drawings I show a fiat plate-like one-piece roll-forged member having various passages therein for refrigerant ow therethrough and this member may be produced in accordance with the roll-forging method described in the patents to G. R. Long #2,662,- 273, dated December 15, 1953, and C. H. Wurtz et al. #2,712,736, dated July 12, 1955. This method is now Well known to those skilled in the art and briefly consists of superimposing metal plates, preferably aluminum alloy plates, one upon another with a predetermined pattern of stop-Weld material applied to the face of one ofthe plates for forming the desired shape of passage or passages between the plates. The superimposed-plates are roll-forged together by passing them between a pair of heated rollers where their thickness is reduced and their contacting surfaces, beyond the pattern of the stopweld` material, are pressure forged together to prov-ide a one-piece homogeneous plate. After roll-forging the plates together the internal passages, determined by the design or pattern of stop-weld material, between the composite or one-piece plate member are dilated by subjecting the same to a fluid pressure while the composite member is confined between suitable blocks or heavy plates in the manner fully explained in the Long patent. When the composite member comes out between the rollers and while it is being dilated it is in a flat form and is thereafter bent along certain predetermined lines to form one portion of the same into a box-like or Ulshaped evaporator element which provides the walls of freezing compartment and another portion thereof into a condenser element of a refrigerating system as disclosedk in the Jacobs and Gould patent hereinbefore referred to.

Referring again to Figure 4 of the drawings it will be noted that the pattern of the stop-weld material applied to one of the plates of the roll-forged plate member provides the same with two separate tortuous refrigerant passages 21 and 22. The passage 21 forms a refrigerant condenser and passage 22 provides the refrigerating system with a compressed refrigerant super heat removing or pre-cooling coil or section. Trimmed as shown the roll-forged plate member is in reality in two integral portions 23 and 24 connected together by a web means or leg 26 formed integrally on the member. The first portion 23 of the roll-forged plate member has passages 27 and headers or accumulators 28 therein providing refrigerant expansion or evaporating duct means. This evaporator portion 23 of the member is bent to form walls of a freezing compartment and is adapted to be moved into cabinet through the opening in its rear wall, normally closed by the panels 16 and 17 and insulation 18 therebetween, so as to locate the evaporator freezing compartment in the upper part of the storage chamber 11. The sealed casing 20 is clamped to a lower part of portion 24 of the roll-forged member, as described in the Jacobs and Gould patent hereinbefore referred to, and is moved therewith toward cabinet 10 to locate the casing in a supported position within the machine compartment 19. The passages 21 and 22 in this second elongated portion 24 of the roll-forged member provide a gaseous refrigerant condenser and a refrigerant precooler therein respectively. A passage or elongated duct 31 intersects and normally connects the outletl or lower end portion of condenser passage 21 with a refrigerant inlet passage 32 communicating with the refrigerant oxpansion duct means 27 and accumulator headers 28. The portion of duct 31 which intersects the outlet end of condenser passage 21 includes an end or tail part 29 which parallels duct 31 and extends beyond the intersection. Duct 31 includes a reduced duct portion 30 whichV provides a shoulder A (see Figure, 7) substantially midway of the length thereof. That part 29, portion 30 and shoulder 30A ofV duct 31, are for apurpose..

to be hereinafter described. This duct 31, as well as a refrigerant return conduit or duct 33 which leads from the evaporator to casing 20, extends through the web 26. It is to be noted that the passages 21, 22, 27 and 32 and the elongated ducts 31 and 33 are all of substantially the same size and internal flow capacity. This, as is well understood in the refrigeration art, requires a refrigerant pressure reducer or restrictor to be provided intermediate the condenser 21 and the evaporator expansion duct means 27 and 28 in order to establish a pressure differential of refrigerant contained in the refrigerating systemv between different elements thereof. In order to prevent rejects, and Waste of roll-forged members having restrictors formed integrally therein of the type disclosed in the Jacobs and Gould patent and to preserve the advantages of such a roll-forged member it is more feasiblev and less expensiveV to provide a refrigerant restrictor'for a roll-forged member in a manner or method other thanthat shown and claimed in this patent.

Referring now to Figure 5 of the drawings, I sever. or cut away a single section of portion 24 of the rollforged plate member, inwardly of its trimmed peripheral edges, as at 36 along with a part or segment of the end or tail 29v of elongated duct 31. The opening 36 provides or formsan edge part on the plate member inwardly of and distinguished from its peripheral edges which exposes or opens tail 29 and consequently one end of elongated duct 31 to this plate edge part and provides access thereto. While I by preference show the elongated duct 31 exposed to said edge part of the roll-forged plate member, provided bythe cut out segment or opening 36, it is to be understood that an end of duct 31 can, be extended to and exposed at a peripheral edge ofthe plate member'. Inl accordance with my invention an element separate from the roll-forged plate is now to be associated with this member for controlling flow of refrigerant from the condenser portion to the evaporator portion thereof., This separate element may be a restrictor tube per se but I preferably provide or also include a dryerlter within the elongated duct 31 for the refrigerating system. The length of restrictor tubing comprises a straight portion or section 37 and an integral section 38 which is coiled in spiral fashionl or formation. The restrictor, tube has an inside diameter throughout its entire length that is, substantially capillary in size as compared to the internal cross-sectional area of the passages and ducts 21, 27 and 31. A resilient means such as a rubberlike cone-shaped washer or grommet 41 is slipped over the end. of, straight section 37 of the restrictor or capillary tube so as to surround a portion thereof and is slid therealong to a point adjacent the start of the coiled section38- of the tube. A similar grommet 42 may bey slipped over the end of the coiled section 38 of the tube. Washers or grommets 41 and 42 may be made of polychloroprene material which will not become deteriorated by refrigerantsV and oils used in present day refrigerating` systems or damaged by heat ordinarily or inherently present in such systems. The end of straight section 37 of the restrictor tube is then inserted into the open or exposed tail end 29 of elongated duct 31, at the opening 36, and is pushed or fed through the reduced portion 30 thereof until the grommet means 41 strikes the shoulder 30A in the duct 31. An additional force is applied to the restrictor tube at this time to compress and wedge the grommet 41 tightly against shoulder 30A, inner wall surfaces of duct 31 and' against the tube to provide a u'id' sealk at this point between Walls of the elongated duct 31 and the tube. It is to be understood that grommet 42 on the coiled section 38 of the restrictortube is fed or pushed into elongated' duct 31 simultane` ously with` feeding of grommet 41 thereinto and this grommet 42 serves to center the: endv Vof the restrictor;

tube; adjacent coiledi section. r38 thereofwithin the, duct.

escasas' suitable wetting substance may be applied tothe grommets 41 and 42 if desired to facilitate their slippage along inner wall surfaces of duct 31. The end of the straight section 37 of the restrictor tube extends through reduced portion 30 of duct 31 beyond the web 26 and terminates within the inlet 32 of the refrigerant expansion passage or passages 27 in portion 23 of the roll-forged member. A filter-dryer 45 comprising a cylindrical screen (see Figure 7) containing a refrigerant drying material such, for example, as granular calcium sulphate or the like is thereafter pushed into the elongated duct 31 so as to be spaced from the open or exposed tail end 29 thereof. After insertion of the restrictor tube and filter-dryer 45 into elongated duct 31 in the manner described the walls of the open or exposed tail end 29 of this duct areV pinched together and these walls are sealingly bonded to one another preferably by a helium arc welding process. In this manneronly a single part orisegment need be cut from the roll-forged plate member and only one separate welding Voperation is required to seal the Aelongated duct 31. VIt. is to be understood that a different arrangement or formation of thepassages and ducts 21, 22, 27 and 33 in the plate member may Vrender it feasible to extend one end of the tail 29 of elongated duct 31 to a peripheral edge of the member in which Ycase the exposed or open end ofduct 31 could be dilated and the restrictor tnbe inserted thereinto. This would eliminate severing or cutting away a segment or part of the portion 24, of the roll-forged member after walls of passages therein have been dilated or spread apart. Such modification is -within the realm of my invention and I do not wish to be restricted in any manner other than by the scope of the claims appended hereto.

In the refrigerating system of the type herein disclosed refrigerant compressed in the sealed casing 20 is first directed out of the casing, through a suitable portr opening,v into the super-heat removing or pre-cooling coil of passage 22 in the roll-forged member and is then returned to the interior upper part of the casing 20. Refrigerant is again directed out of casing 20 into the tortuous refrigerant condenser passage 21 where it is cooledand liquiiied. Air circulating in the flue between the cabinet back wall and portion 24 of the roll-forged member is utilized to cool refrigerant in the super-heat removing duct 22 and to cool yand liquefy refrigerant in the condenser duct or passage 21. The liquilied refrigerantY enters elongated duct 31 from passage 21 and ows through vthe dryer-filter 45 and the restrictor tube through the web means 26 into the inlet 32 of the evaporator or refrigerant expansion duct means 27 and 28 wherein it absorbs heat from chamber 11 of cabinet 10 and vaporizes. At least grommet 41 prevents circulation of the liquified refrigerant into the space between walls of vthe reduced duct portion 30 and the restrictor tube whereby all the liquid refrigerant is required `to ow through the capillary tube. Any refrigerant that may leak past grommet 42 Will be blocked by the tightly wedged grommet 41 from owing into the evaporator inlet 32. Thus liquid refrigerant can enter the evaporator portion of the roll-forged member only under the control of the restrictor tube. Cool vaporous or gaseous refrigerant leaves the evaporator by way of'the return duct 33 and is conducted along the second portion 24 of the roll-forged member back into the compressor within casing y.20 through a suitable connection between the rollforged member and this casing. It will be noted that l havekforme'd both the duct 30 and the refrigerant return duct 33 in close side byside proximity or relationship in web 26 and through the major part of their lengths in portion 24 of the roll-forged member. The restrictor tube within elongated duct 31 is thus disposed in good heat exchange relationship with the cool refrigerantireturn duct 33. The refrigerating system may be cyclically operated by a suitable temperature responsive thermostatic control device as is conventional in the art.

The manner and method herein disclosed of providing a refrigerant restrictor or control for use with a plate; like combined evaporator and condenserrforming member is economical, of low manufacturing cost and permits a portion of the member, through which a capillary tube extends, to be bent without danger of pinching the restrictor tube closed. My invention serves to render the use of roll-forged combined element forming members in refrigerating systems practical and without rejects or waste of these members. My improved structure pro-v vides for the conduction of condensed liquifed refriger ant from one portion of a'unitary combined element forming roll-forged member of a refrigerator system to another remote portion thereof without evaporation in its course of travel whereby to confine absorption of heat to the heat absorber or evaporator element or portion of the member. While lthe restrictor is a capillary tube separate from the roll-forged member it is wholly disposed within and concealed by the member and is plugged in a duct thereof in a manner which causes all refrigerant to ow therethrough whereby the tube forms the sole means for controlling entranceV of refrigerant into the evaporator portion, of the member. The provision of receiving a coiled section of the restrictor tube in the elongated duct of the plate member reduces the overall length of the tube, and the coil length thereof can be varied, while being concealed within the member, to ob tain the proper restriction of refrigerant ow for different sized evaporators. It should be apparent from this that l have utilized all the advantages of a one-piece roll-V forged plate member and a separate capillary tube to provide a simplified and economical refrigerating system.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. In a refrigerating system, a sheet metal plate member having means forming a refrigerant condensing passage in one portion thereof, means forming a refrigerant expansion passage in another portion thereof and means forming an elongated duct extending between said por-l tions of said member and connecting the outlet of said condensing passage to the inlet of said expansion passage, said elongated duct having an end thereof extending to and exposed at an edge part of said plate member, a tube separate from said member inserted into said elongated duct at the exposed end thereof and projected through the duct beyond said one portion of said member with one of its ends terminating at a point adjacent/the inlet of said refrigerant expansion passage and with its other end spaced inwardly of the exposed end of said duct, a resilient grommet surrounding a portion of said tube intermediate ends thereof and wedged against inner wall surfaces of said duct and said tube to provide a fluid tight seal therebetween, means sealingly bonding Walls of said duct at said exposed end thereof, said seals cooperating to cause refrigerant entering said elongated duct to be directed into said otherend of said tube, and

the inside diameter of said separate tube being of substantially capillary size as compared to the cross-sectional area of said passages in said plate member for controlling the flow of refrigerant from said condensing` passage to said expansion passage inlet.

2. A member of a refrigerating system as defined by claim l wherein the other portion of the member is disposed within a chamber of a refrigerator cabinet and is bent to provide walls of a freezing compartment therein and the one portion of the member has a part thereof spaced from the cabinet back wall to form a vertical air iiue therebetween. A

3. A member of a refrigerating system as dened by claim l wherein a web means formed integrally thereon joins the portions thereof to one another and the clon gated duct extends through the web means.

7 `4, In, a refrigerating -system,. a. one-piecev roll-forged plate'. member having a. plurality of passages formed therein, said member comprising a first portion with the passages. therein forming refrigerant expansion duct meas'jto'provide an evaporator in said system and a second. portion spaced. from said first portion and connected Vthereto by web. means formed integrally with said portions, one of the passages Within said second portion of said'rollforged plate member providing a refrigerant condenser in. said system, another of the passages within saidsccond portion ofsaid memberforrning an elongated duct intersecting an outlet. end of said condenser passage and. extendingl through. said web means to normally establish communication between said outlet end of said condenser passage and an inlet `of said expansion duct means an end of said elongated duct extending to and being exposed atan edge part of said plate member, a tube separate-from. said member inserted into the exposed end of said elongated duct and` projected through the duct beyond said -web means with one of its ends terminating at a point. adjacent the inlet of said evaporator expansion duct means and with its other end spaced inwardly of the exposed end of said elongated duct, a resilient grommet surrounding said separate tube Within said. second portion of said member intermediate ends of the tufbe, said grommet being wedged against the inner wall surfaces of said elongated duct and said tube to provi'de a fluid tight seal therebetween, means sealingly bondingvwalls of said elongated duct at said exposed end thereof, said seals cooperating to cause refrigerant entering said elongated duct to be directed into said other end of said tube, `and the inside diameter of said separate tube., being of. substantially capillary size as compared to..` the cross-sectional area of the passages i-n said rollforgedplate member for controlling the ow of refrig erant from said: condenser to said evaporator.

5. A member of a refrigerating system as deiined by claim. 4 wherein theiirst portion of the member is disposedwithin a chamber of a refrigerator cabinet andv is bent to provide walls of a freezing compartment therein and the second portionv of the member has a part thereof spaced` from the cabinet back wall to form a vertical air ue therebetween.A

6. In a refrigerating system, a one-piece roll-forged plate. member having a plurality of passages formed therein, said member comprising a lirst portion with the passages therein forming refrigerant expansion duct meansto provide an. evaporator in said system and a second portion spaced from said` first portion and connected thereto. by web means formed integrally with said portions, one of the passages within said second portion of; said roll-forged. plate member providing a refrigerant condenser in. said system, another of the passages within saidsecond portion of said member forming an elongated duct intersecting an outlet end of said condenser passage andextending through said web means to normally estab lish. communication between said outlet end of said condenser passage andan inlet of. said expansion duct means, a part of said second portion of the roll-forged member withv a segment of said intersecting elongated duct being cut away inwardly of the peripheral edges of the member toexpose an end of the elongated duct, a tube separate from said member having a straight section and a section coiled in spiral formation inserted into the exposed end of,.said elongated duct, an end of the straight section of said. tube terminating at a point adjacent the inlet of said evaporator expansion duct means and an end of the coiledsection of said tube being spaced inwardly of the exposed end of said elongated duct, a resilient grommet surroundingaportion ofthe straight section of said tube adjacentv the coiled section thereof and'wedged against the inner wall. surfaces ofsaid` elongated duct and said tube to provide aiiuid tight sealtherebetween, means.. sealingly bonding walls of said elongated duct at said exposed end thereof, said seals cooperating to cause re frigerant entering said elongated duet to be directed into. the end of the coiled section of said. tube, and the inside diameter of said separate tube being of substantially. capillary size as compared to the cross-sectional area of the passages in said roll-forged plate member for controlling the ow of refrigerant from said condenser to said evaporator. y

7. A member of a refrigerating system as defined by Y claim 6 wherein the tirstportion of the member is dis-A posed within a chamber of a refrigerator cabinet and is bent to provide walls of a freezing compartment therein and the second portion of the member hasa part thereof. spaced from the cabinet back wall toform avertical air flue therebetween.

8. In a refrigerating system, va one-piece roll-forged plate member having a plurality of passages formed therein, said member comprising a first portion with the passages therein forming refrigerant expansion duct means to provide an evaporator in said system and a second portion spaced from said first portion and connected thereto by web means formed integrally with said portions, one of the passages within said second portionv of said roll-forged plate member providing a refrigerant condenser in said system, another of the passages within said second portion ofsaid member forming an elongatedduct, said elongated duct including a first portion inter.- secting an outlet end of said condenser passage and a reduced portion extending through said web means and v communicating with an inlet of said expansion duct means, an end of said first portion of the elongated duct extending to and being exposed at an edge part of said plate member, a tube separate from said member having a straight section anda section coiled in spiral formation, said tube being inserted into the exposed end of saidl rst portion of the elongated duct with its straight section. disposed in said reducedl portion thereof and with its coiled section disposed in the irst portion of said elongated duct, the open end of said straight section of said tube terminating at a point adjacent the inlet of said evaporator expansion duct means and the open end of said' coiled section of said tube being spaced from said edge part of the plate member, the connection between said portions of said elongated duct providing a shoulder therein, a resilient grommet surrounding a part of the straight section of said tube adjacent the coiled section:

thereof and wedged against said shoulder and said tube to provide a uid seal therebetween, means sealingly bonding walls of said elongated duct at said exposed end thereof to wholly conceal said tube therein, said seals cooperating to cause refrigerant entering said elongated duct to be directed into the coiled section of, said tube,-

and the inside diameter of said separate tube being of substantially capillary size as compared to the cross-4 Savidge Aug. l0,A 19748 Thomas. Jan. 8, 195.7 

